package top.gangster.lunan.userservice.interceptor;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import java.lang.reflect.Method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import top.gangster.lunan.userservice.annotation.LoginToken;
import top.gangster.lunan.userservice.annotation.PassToken;
import top.gangster.lunan.userservice.entity.User;
import top.gangster.lunan.userservice.service.UserService;

public class JwtInterceptor implements HandlerInterceptor {

  @Autowired
  private UserService userService;

  /**
   * 前置拦截器，用于登录验证
   * @param httpServletRequest 参数HttpServletRequest
   * @param httpServletResponse 参数HttpServletResponse
   * @param object 参数Object
   * @return t/f
   */
  @Override
  public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {
    String token = httpServletRequest.getHeader("token");// 从 http 请求头中取出 token
    // 如果不是映射到方法直接通过
    if(!(object instanceof HandlerMethod)){
      return true;
    }
    HandlerMethod handlerMethod=(HandlerMethod)object;
    Method method=handlerMethod.getMethod();
    //检查是否有passtoken注释，有则跳过认证
    if (method.isAnnotationPresent(PassToken.class)) {
      PassToken passToken = method.getAnnotation(PassToken.class);
      if (passToken.required()) {
        return true;
      }
    }
    //检查有没有需要用户权限的注解
    if (method.isAnnotationPresent(LoginToken.class)) {
      LoginToken loginToken = method.getAnnotation(LoginToken.class);
      if (loginToken.required()) {
        // 执行认证
        if (token == null) {
          throw new RuntimeException("无token，请重新登录");
        }
        // 获取 token 中的 user id
        String userId;
        String uid;
        String username;
        String password;
        String roleId;
        try {
          userId = JWT.decode(token).getAudience().get(0);
          System.out.println(userId);
          username = JWT.decode(token).getAudience().get(1);
          System.out.println(username);
          password = JWT.decode(token).getAudience().get(2);
          System.out.println(password);
          roleId = JWT.decode(token).getAudience().get(3);
          System.out.println(roleId);
          uid = JWT.decode(token).getAudience().get(4);
          System.out.println("uid"+uid);
        } catch (JWTDecodeException j) {
          throw new RuntimeException("401:token已过期");
        }
          User user = userService.getUser(userId);
        if (user == null) {
          throw new RuntimeException("401:用户不存在");
        }
        // 验证 token
        JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPassword())).build();
        try {
          jwtVerifier.verify(token);
        } catch (JWTVerificationException e) {
          throw new RuntimeException("401:token错误");
        }
        return true;
      }
    }
    return true;
  }

  @Override
  public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

  }
  @Override
  public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

  }
}

